Method findTerminalField

src/document/forms/field-tree.ts:233–241

* Find a terminal field by name.

(name: string)

   * Find a terminal field by name.
   */
  findTerminalField(name: string): TerminalField | null {
    const field = this.findField(name);

    if (field && field instanceof TerminalField) {
      return field;
    }

    return null;
  }

  /**
   * Get the number of fields (including non-terminal).